Articular cartilage is prone to diseases, such as chondromalacia and osteoarthritis, which result in fibrillation, or fraying, of the cartilage. Damaged cartilage is not as effective in maintaining stiffness and resilience, and in minimizing stress due to load. The diseases tend to degenerate over time if left untreated, and can result in the total loss of articular cartilage in the joint. It is desirable to treat these diseases to re-establish a smooth, stable articular surface.